CAMRT Radiography Practice Exam

A high grid ratio is associated with a smaller focusing range. The focusing range of a grid refers to the distance within which the primary x-rays should be directed in order for the grid to effectively absorb scatter radiation while allowing the primary beam to pass through.

When a grid has a high ratio, it means that the grid strips are relatively tall compared to their interspace material. This design leads to a stricter requirement on the angle of the x-ray beam entering the grid. Consequently, this results in a more limited range of acceptable distances and angles from which the central ray can approach the grid. As a result, the high grid ratio effectively necessitates a smaller focusing range to ensure optimal image quality.

Additionally, grids are often categorized by their ratio – for example, a grid with a 16:1 ratio will have a tighter focusing range than a grid with a 5:1 ratio. Thus, the nature of a high grid ratio indeed contributes to a smaller focusing range, making the provided answer correct.